Is sealing chrome valve covers hopeless ?
 

I bought a pair of nice, straight lipped, chromed, Pent roof valve covers. I can't get one outside edge to seal. I don't want to use silicone, because I lash the valves twice per year. I replaced the cork gaskets with rubber, no change. Is sealing them hopeless without silicone ?

Kev, I made a post about this a while back, try a search under my name.

Mine have never leaked since day one.

Thanks Sal, I'll look it up bud. Do you have a link to it ?

Get rid of the chrome at the base of the covers. Same holds true for a chrome oil pans.

Where the intake forms the top 1/3 of the valve cover mating surface and the head forms the bottom 2/3, it is possible that these two surfaces are not on the same plane. When blocks are decked and heads are plained, the intake must also be machined to keep all this matched up, and it doesn't alway get done right or even done at all.

I had a 2.9 in a Bronco II (essentially the same design) that these surfaces were off over 1/8". The only time I ever got it to not leak over time was when I pitched the gaskets and filled it with ultra coper. Not saying you should do this or that you have this problem, but you should check it with a straight edge next time the covers are off.

Well shoot, even I can't find the post now.

Okay, on my car.... first thing, you need to make sure the "tang" from the intake gasket that sticks up between the intake and the head, is LEVEL or lower than the metal surface. If it's not, it pushes the gasket up and you get the dreaded corner leaks. It's also important to have your head and intake surface pretty even (as olddog stated). Mine were a good 1/8" off, but a cork gasket will compensate for that.

Now for the sealing... I use some quality RTV on all 4 points where the heads and intake meet. If you don't do this, oil will leak there. For the gasket itself, I use the cork Fel-pro Printoseal gaskets. I am not a fan of rubber valve cover gaskets. First, I inspect the valve covers themselves, making sure the sealing lips are straight and level, and making any needed tweaks with a wide flat lip plier. Once straight, I use 3M super weatherstrip adhesive (comes in yellow and black) to seal the cork gasket to the cover. I let it tack, then put the gasket on, then place the cover on a flat table letting the weight hold the gasket in place. It also helps to put the bolts through the holes to also hold the gasket better.

Once adhered to the cover, I clean the head and intake surface with metal prep, and then install the covers, making sure not to overtorque them.

With this method, I have never had any pentroof I ever installed leak. The downside is if you need to replace the gasket, it's a tedious job getting it off the cover because of the 3M. But you can take the covers on and off a few times before the gasket won't squish down any more, so you might just have to change the gasket once a year.

Hope this helps.

Just buy the silicone valve cover gaskets from a place like Summit Racing. They have a metal core and the sealing surface is silicone. It will form to your surfaces, unlike rubber or cork.

They are not cheap, but I've never had a leak using these type of gaskets in any engine.

Kevin,

Here is what I do if it will help.

1. make sure the lips of the valve covers are flat and straight.
2. clean with starting fluid.
3. use thick cork gaskets.
4. gather the bolts that go through the covers
5. place a thin coating of RTV ( pick a color like black ) over the lip(s).
6. carefully place the gasket on the cover and press down.
7. use the bolts to align the gasket.
8. allow to dry.
9. apply a thin seal coat of RTV over the now attach gasket.
10. allow it to dry.
11. strange as this sounds, use a small torque wrench and tighten to 10 foot pounds as you install the covers.

These do not leak and can be pulled off a number of times. The coating on the gasket coupled with the 10 foot pounds should allow you to use this for a long time.

Hope this helps!

:D :D :D

Anyone ever try bead blasting the valve-cover gasket surface? This will give the gasket a surface it can "bite" into.

As Power Surge said, 3M's "gorilla snot" between the valve cover and gasket will hold it in place, but it is a bear to get the old gasket material off when replacing gaskets. Stops leaks, though.

Evolution is a good thing. A skim coat of Permatex "The Right Stuff", will make you forget what silicone in a tube ever was.....and use the thickest cork gaskets available.

Trularin is dead on, cork is a much better material to use with sheet steel covers.

Like everyone else has said, make sure everything is flat/true and lightly torque your cork gaskets. When the oil hits 'em they'll swell slightly and seal off any small gaps.

At least until your sheet metal covers start distorting again...%/

Cork really works best (with any cover) but most people lean on the wrench to hard. Nice, spongy gaskets are what you need here.

On engines where we know the valve cover will be coming off very soon...We use "The Right Stuff" to glue the valve cover gasket down to the head. On any other engine we would glue the gasket to the valve cover, but on an FE with the manifold mating to the head under the valve cover, we glue the gasket to the head (and of course the manifold). We also put a little blob where the intake and the head come together. This "Right Stuff" is a silicon that was developed by GM to replace gaskets. It works MUCH better than any other silicon type product we have ever used.

I found a company that markets a great extra thick cork gasket for the FE valve covers. I recommend them when using chrome valve covers on my valve cover adapter kits. If you mount the gaskets onto the valve cover using Permatex hi-tack gasket adhesive or a bead of Permatex Ultra Black Gasket Silicone they work great. Of course, you do have to place a dab of sealer at the intake-head joint on the FE motors.
http://www.dscmotorsport.com/